Multiple Players in the Mechanical Control of T Cell Quiescence

Naive T cells are kept in a quiescence state, characterized by small cell size, with low proliferative and metabolic activities, until antigen engagement. T lymphocyte quiescence is a tightly controlled mechanism regulated by multiple quiescence‐associated factors. Loss or impaired functions of these factors regularly result in spontaneous activation of T cells that is ensured by fatal autoimmune diseases. Elucidating the mechanism to facilitate the switch on or off of T cells could be beneficial to ameliorate pathology triggered by T cell hyperactivation or dysfunction. In this chapter, we discuss multiple quiescence‐associated factors along with the mechanisms utilized to promote lymphocyte quiescence and longevity

Immunomodulatory effects of 17-O-acetylacuminolide in RAW264.7 cells and HUVECs : involvement of MAPK and NF-κB pathways

The terpenoid 17-O-acetylacuminolide (AA) was shown to inhibit the production of several inflammatory mediators. However, the mechanisms by which this compound elicited its anti-inflammatory activity remain to be elucidated. In this study, we analyzed the effects of AA on inflammatory gene expression in two different cell types with primordial importance in the inflammatory processes-endothelial cells and macrophages. In human umbilical vein endothelial cells, AA inhibited the expression of inflammatory proteins including the adhesion molecules intercellular adhesion molecule 1; vascular cell adhesion molecule 1; and E-selectin, as well as the release of the chemokine interleukin-8. Additionally, AA hindered the formation of capillary-like tubes in an in vitro model of angiogenesis. AA's effects in endothelial cells can be attributed at least in part to AA's inhibition of tumor necrosis factor alpha-induced nuclear factor of kappa light polypeptide gene enhancer in B-cells (NF-kappa B)'s translocation. Also, in lipopolysaccharide-stimulated macrophage-like RAW264.7 cells, AA was able to downregulate the expression of the genes cyclooxygenase 2, inducible nitric oxide synthase, interleukin-6, and chemokine (C-C motif) ligand 2. Moreover, AA inhibited the phosphorylation of nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor-alpha (I kappa B alpha), I kappa B kinase (IKK), and the mitogen-activated protein kinases JNK, ERK, and p38. In conclusion, the present results further support the anti-inflammatory potential of AA in different models of inflammation

Gallic acid attenuates dextran sulfate sodium- induced experimental colitis in BALB/c mice

Gallic acid (GA) is a polyhydroxy phenolic compound that has been detected in various natural products, such as green tea, strawberries, grapes, bananas, and many other fruits. In inflammatory bowel disease, inflammation is promoted by oxidative stress. GA is a strong antioxidant; thus, we evaluated the cytoprotective and anti-inflammatory role of GA in a dextran sulfate sodium (DSS)-induced mouse colitis model. Experimental acute colitis was induced in male BALB/c mice by administering 2.5% DSS in the drinking water for 7 days. The disease activity index; colon weight/length ratio; histopathological analysis; mRNA expressions of IL-21 and IL-23; and protein expression of nuclear erythroid 2-related factor 2 (Nrf2) were compared between the control and experimental mice. The colonic content of malondialdehyde and the activities of superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase activity were examined as parameters of the redox state. We determined that GA significantly attenuated the disease activity index and colon shortening, and reduced the histopathological evidence of injury. GA also significantly (P<0.05) reduced the expressions of IL-21 and IL-23. Furthermore, GA activates/upregulates the expression of Nrf2 and its downstream targets, including UDP-GT and NQO1, in DSS-induced mice. The findings of this study demonstrate the protective effect of GA on experimental colitis, which is probably due to an antioxidant nature of GA

Signal Transducer and Activator of Transcription (STATs) Proteins in Cancer and Inflammation: Functions and Therapeutic Implication

Signal Transducer and Activator of Transcription (STAT) pathway is connected upstream with Janus kinases (JAK) family protein and capable of integrating inputs from different signaling pathways. Each family member plays unique functions in signal transduction and crucial in mediating cellular responses to different kind of cytokines. STAT family members notably STAT3 and STAT5 have been involved in cancer progression whereas STAT1 plays opposite role by suppressing tumor growth. Persistent STAT3/5 activation is known to promote chronic inflammation, which increases susceptibility of healthy cells to carcinogenesis. Here, we review the role of STATs in cancers and inflammation while discussing current therapeutic implications in different cancers and test models, especially the delivery of STAT3/5 targeting siRNA using nanoparticulate delivery system

Boldine suppresses dextran sulfate sodium-induced mouse experimental colitis: NF-&#954;B and IL-6/STAT3 as potential targets

Ulcerative colitis (UC) is a nonspecific inflammatory disorder characterized by oxidative and nitrosative stress, leucocyte infiltration, and upregulation of inflammatory mediators. Boldine is an alkaloid compound found in Boldo tree, with multiple pharmacological actions, mainly anti-inflammatory, antioxidant, antitumor, and immunomodulatory activities. Hence, the effect of boldine for its anti-inflammatory properties against dextran sulfate sodium (DSS)-induced UC in BALB/c mice was studied. Administration of boldine to DSS-induced mice protects colon damage by reduced disease activity index, spleen weight, and increased colon length. Also administration of boldine showed a reduction in the activity of myeloperoxidase (MPO) and CD 68+ expression. Boldine reduced the colon damage, with significant reductions in both the extent and the severity of the inflammation as well as in crypt damage and leukocyte infiltration in the mucosa. Analysis in vivo showed clear decrease in the production of tumor necrosis factor (TNF)-α, Interleukin (IL)-6, IL-17, and signal transducer and activator of transcription-(p-STAT3)(Y705) with nuclear factor (p65-NF-κB) production being reduced significantly. Moreover, p65-NF-κB activation was reduced in mouse macrophage RAW 264.7 cells in vitro. The data demonstrated that boldine may be beneficial in colitis through selective immunomodulatory effects, which may be mediated, at least in part, by inhibition of p65-NF-κB and STAT3 signaling pathways

Boldine suppresses dextran sulfate sodium-induced mouse experimental colitis: NF-&#954;B and IL-6/STAT3 as potential targets

Ulcerative colitis (UC) is a nonspecific inflammatory disorder characterized by oxidative and nitrosative stress, leucocyte infiltration, and upregulation of inflammatory mediators. Boldine is an alkaloid compound found in Boldo tree, with multiple pharmacological actions, mainly anti-inflammatory, antioxidant, antitumor, and immunomodulatory activities. Hence, the effect of boldine for its anti-inflammatory properties against dextran sulfate sodium (DSS)-induced UC in BALB/c mice was studied. Administration of boldine to DSS-induced mice protects colon damage by reduced disease activity index, spleen weight, and increased colon length. Also administration of boldine showed a reduction in the activity of myeloperoxidase (MPO) and CD 68+ expression. Boldine reduced the colon damage, with significant reductions in both the extent and the severity of the inflammation as well as in crypt damage and leukocyte infiltration in the mucosa. Analysis in vivo showed clear decrease in the production of tumor necrosis factor (TNF)-α, Interleukin (IL)-6, IL-17, and signal transducer and activator of transcription-(p-STAT3)(Y705) with nuclear factor (p65-NF-κB) production being reduced significantly. Moreover, p65-NF-κB activation was reduced in mouse macrophage RAW 264.7 cells in vitro. The data demonstrated that boldine may be beneficial in colitis through selective immunomodulatory effects, which may be mediated, at least in part, by inhibition of p65-NF-κB and STAT3 signaling pathways

β Mangostin suppress LPS-induced inflammatory response in RAW 264.7 macrophages in vitro and carrageenan-induced peritonitis in vivo

Ethnopharmacological relevance: The fruit hull of Garcinia mangostana Linn. has been used in traditional medicine for treatment of various inflammatory diseases. Hence, this study aims to investigate the in vitro and in vivo anti-inflammatory effect of β mangostin (βM), a major compound present in Garcinia mangostana. Materials and methods: The in silico analysis of inflammatory mediators such as cyclooxygenase (COX) and nuclear factor-kappa B (NF-kB) were performed via molecular docking. Further evaluation of anti-inflammatory effect was conducted in lipopolysaccharide (LPS) induced RAW 264.7 macrophages. Suppression of activated NF-kB was analyzed by high content screening. βM triggered inhibition of COX-1 and COX-2 in vitro were studied using biochemical kit. The in vivo model used in this study was carrageenan-induced peritonitis model, where reduction in carrageenan-induced peritonitis is measured by leukocyte migration and vascular permeability. In addition, the evaluation of βM׳s effect on carrageenan induced TNF-α and IL-1β release on peritoneal fluid was also carried out. Results: Treatment with βM could inhibit the LPS-induced NO production but not the viability of RAW 264.7. Similarly, βM inhibited PGE2 production and the cytokines: TNF-α and IL-6. The COX catalyzed prostaglandin biosynthesis assay had showed selective COX-2 inhibition with a 53.0±6.01% inhibition at 20 µg/ml. Apart from this, βM was capable in repressing translocation of NF-kB into the nucleus. These results were concurrent with molecular docking which revealed COX-2 selectivity and NF-kB inhibition. The in vivo analysis showed that after four hours of peritonitis, βM was unable to reduce vascular permeability, yet could decrease the total leukocyte migration; particularly, neutrophils. Meanwhile, dexamethasone 0.5 mg/kg, successfully reduced vascular permeability. The levels of TNF-α and IL-1β in peritoneal fluid was reduced significantly by βM treatment. Conclusion: The current study supports the traditional use of Garcinia mangostana fruit hull for treatment of inflammatory conditions. In addition, it is clear that the anti-inflammatory efficacy of this plant is not limited to the presence of α and γ, but β also with significant activity